Laptop LCD screen

My acer laptop screen has recently stopped working. I'm currently using an external monitor since the screen is so dark it's almost impossible to see anything. I read on another post that this is commonly due the to backlight burning out, but first to check the backlight hasn't been toggled off.

So i've hit Fn and F6 to toggle the backlight and it will flick on for a few seconds but then goes dark again...this suggests to me its not a burnt out backlight but some other problem...any ideas??

Sounds like the inverter, which is the high voltage unit, not much larger than a Sharpie pen, that converts negative image to positive. Nearly every laptop has a slightly inverter, but you can often buy them at ebay or laptop repair sites for $11 to $25. The list price from the manufacturer can be the robbery price of up to $79.
You need a set of small screwdrivers, then you need to remove the litte rubber or asphalt pasties that cover the screws. The inverter runs down one of the four sides behind the lcd screen.
You can find descriptive information on line by doing a Gurgle search for laptop screen repair, or replacing laptop inverter. I don't remember the exact site.
If you are not good with tools, it is wise to buy the inverter yourself, but hire a good tech to install it for about $55.